Automatic firearm.



K. KRNKA, AUTOMATIC IIBBARM.

AXPLIOATION FILED JUICY 12,

2 SHEETS-BHEBT l. v

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KARL KRNKA. OF HRTEN BERG. AUSTRIA-HUNGARY.

AUTOMATC FIREARM.

Specification of Letters fatent.

Fntentetl. Feb. f",

Appneano ined July 1:2, 1.909. serial no. 507,157.

To ail 0.7mm zfmay concern Ee it known that L Yann KRNK. engi neer, a Subject of the Emperor of Austrial-l'nng'ary, residing; :it Hirtenberg', in the Province of Lower Aust ia. Empire ot' Austriz'i-Huiig'ary, have invented certain new and nezeful improvements in utomatie Fire-arms; and I do hereby declare the. following to be n tnlll` clear, and exact description ot the invention, Such as will enable othere` Skilled in the art to which it appertnins to nnile and use the saine.

The presient inrention relates to improved breech block for nutoniatie vtrrearnis. which is designed by its simplicity and by the Small nninber of parte for producing automatie operntion. sind which also enables a firearm of thi: character be mede. with n relatively short and 'self-fontained breeeh Automatic: -firenrins are `Known. in n'liiih n Very short. baeitnartl nioreinent is imparted to the breech bloei; by the explosion of the cartridge, backward movement being' transmitted to a nionientnni bloeit which is in contact Withithe. breech bloeit. the inonientnni block.y owingr to the energyimparted 'f it. being thereby actuated torv operating n unlockingy member to open the breech and operatingr the Firearm. Y

The object of this invention is to apply thisv principle to a breech inerhaniein having a rotary loelt.

The. invention ronsistn in :in improved breeeh bloeit. edinprising a sliding; and rotary loeltingr breeeh bolt sleeve. a breech bolt for lurkingl and nnlorking the breech bolt sleeve, and a. breeeh bolt nlug ('apable ot' having' :i relatively small independent niovement for efllecting the initial unlocking` movement of said brew-h bolt sleeve. :ind iininediately thereafter eli'eetiug the complete unlocking' niort-nient and opening the breerh bolt ysleeve through the `aas pressure produeed. inthe run barrel` 'l1`he invention further proposes lo utilize nn areuniulnior, as in heavy ordininre. to the end oi' 1etui-ing energy through the opening niorenient of the breeeh bolt sleeve. and utilizing said energy to vlose and lot-lt the breech bolt lleeve, and cork the tiringr pin under tension.

llritlnthese. nndtlier ,oblieris in View the invention consists in the novel leiiiils ot construction and Combinations of parte more fully hereinafter tliseloseclanfgl particularly pointed out in the Claims.

eerring to the accompanying drawings forn'iing a part of this eneeitiention in which like nnnierele designate like parte in all Figure. l is a central longituthe iiiews: dinal section of a tirearni, with parte in elevation. Showing the application oi? the present invention. Fig. 2- is .ihorizontal longitudinal Sertional View ot Fig. l. 3 is n transverse sectional View of Fig. l, taken on the line S-F. Fig. 4 is n trane- Verse Sectional View of the breech easing. taken on the line l-l of Fig'. l. Fig. 5 is a detail elevational vienY of the breech bolt shown in Fig. l. Fig'. t3 :i longitudinnl sectional View otl the breech bolt. sleeve. Fig. i is n partial rien' nl the developed breech bolt sleeve.

lfig'. 8 is a Central li. tinlinal Seetionzl Viewpartly in elem .e ot' a modified construction ot breech heb; sieere and breeehbolt. Eig. i) iej n View similar to Fig'f 9. o't` a further inodiried vorn struction. and Fig'. l0 i.--1 a detziil elerntiii-nr," View of :i further proloosed Construction breech bolt. Sleeve.

Referring to the Construction in detnih l designates the stock oiL n ritle. and breech bolt casing' therefor, and n'hieh a screw-threaded connection Il with the barrel 4, as in the usual manner. l breech raising; Q eontuins the breech bolt slee-we Fi. which hns; rotary loeling engrngenieni with the easing 2 through the inediinno opnositei" disposed Ypaire of lugs i3 (see Fig. '2). The linge fit within Suitable slots 'i ot the in eti'ert rotary locking engagement therewith, und through the inednun nlz lnnritudinni slots, not shown. in the easing. said -l sain have longitudinal inoi'enient. hereby the breech bolt sleeve niay .ende within the inning chamber P for opening the. breech. :in will be readiljiv undereftnod.

The slots 'i' nre of the required pitch to eiiect a. turning aetinn upon the bien i5 to the end ot` tightly Closing' the breech sleeve by a rotary inorenient thereof, ne wu now be explained: 'lhe breech bolt. leere lockingr and unlorlting member eoinnrieee. n breeeh boltl that is nun'uble reetilinenrljiy in the breefzl ensinnj 2 through `the inediuni of sti-night guideways l0. within n'liieh ti'nrel the ehouliiers l1 ot #nid bolt. The bolt i) is designed to eilert n, rntary name ment of the breech bo *l it sleeve 5, und 'to min end is provided with two pairs of oppositely disposed and inclined lugs 12, which move within spiral guideways 13 of the breech bolt sleeve 5, as shown in Figs. 6 and 7. Since the breech bolt 9 can have only a rectilinear movement within the breech casing 2, it will be. apparent that when such movement is imparted to the'breech bolt that the breech bolt sleeve 5V will be given a rotary movement to be unlocked or locked, accordingly as said breech bolt is movingr in a forward or rearward direction.

The breech bolt 9 is designed to be actuated to impart an initial unlocking movement` to the breech bolt sleeve 5 instantaneously with the firing of the cartridge, and to this end a breech bolt plug 14 isv provided. rThe breech bolt plug 14 is mounted within the forward end of the breech bolt sleeve 5, and is designed Lo have a relatively short axial movement independently of said, breech bolt sleeve. The extent of this .independent movement, indicated by thc character 15, is designed to be about 0.5 or 3.0 millimeters. The .plug 14 is secured against axial displacement in thev breech boltsleeve 5 through the medium of'lugs 16, Htting within an annular groove 17 on the inner face of the breech bolt sleeve 5 (see Figs. 1, 2, and 6). The dimensions of the lugs 16 with respect to the groove 1T are such that the plug 14 may have axial movement independent of the breech bolt sleeve 5, but is thereafter carried rectilinearlv by the bolt plug', as will be understood. rThe annular groove 17 permits of the breech bolt sleeve 5 having rotary movement independently of the plug 14.

The plug 14 is at all times in abutment with the breech bolt 9, to eli'ect, as above stated, the initial unlocking movement l the breech bolt sleeve, but immediately thereafter said breech plug 14 contacts with the breech bolt sleeve 5, and on its further recoiling movement causes the breech bolt 9 to unlock the breech bolt sleeve 5 from the casing 2, and move the breech bolt sleeve to fully open position to eject the shell of the spent cartridge.

The firing pin 19 is mounted within the breech bolt 9, and is guided rectilinearly therein by a pair of oppositely disposed projections 20, of acollar21,within straight' guideways 22 in said breech bolt. The actuating spring 23 of the firing pin is contained Within the bolt 9, and has its ends abutling respectively, against a seat 24 of 'the bolt l), and the collar 21 of the tiring pin. .l head secured to one end of said tiring pin is constructed with guides 2G p movable within the guidevvays 10 of the breech casing 2, and also in guiding the tiring pin rectilincurly within the bolt E). The head 25 is constructed with a shoulder 2T for engaging with a' sear 28, that is pivotally mounted at 29 to the breech casing 2,

for holding the firing pin cocked and under tension of the spring 23. The Sear 28 is designed to be released from the shoulder 27 by the trigger' 30 through the medium of an intermediate piece 31. TheAA forward end of the firing pin 19 is designed with a conical head 32 that enters Within and projects through a similarly designed recess in the breech bolt plug 14.

Thecartridge extractor 34 has the usual form of a forked spring, and is mounted in a groove in the bolt plug 14 in such manner that it shares the independent movementof said plug, in order that its claws shall not be raised toward the front by the recoil when cartridges having grooved rimsl are used. The shell extractor 34 serves to guide the plug 14 rectilinearly, and' this movement of said plug 14 is further governed by the cartridge ejector rod 35, which engages Within a slot in said plug. The ejector rod 35 has a projecting lug 36 movable Within a relatively short slot 37 in the lower guiding member 11 of the bolt plug 9. Through the medium of this lug and slot engagement (36 and 37), the ejecting end of the rod 35 is permitted to protrude the .necessary distance beyond the plug 14 to engage with the base of the spent cartridge shell and with the help of the extractor head 34, to eject said shell from the breech casing. In the present construction, the cartridge ejector rod 35 has also the purpose of enabling the entire breech mechanism to be made relatively short, sincc its rear fork allows the ring pin shoulder 27, after the pulling of.'V

the trigger, to move forward into the `magazine Without coming in contact with the cartridges therein.

The arrangement for feeding the cartridges is more fully described and shown in my application Serial No. 507,402, dated July 13, 1909, and entitled Improvements in drum magazines for firearms.

The means for closing and locking the breech bolt sleeve following its recoilunder gas pressure, consists in an accumulator spring 3S contained within a` telescoping cylinder, one section 39 of which is secured to the breech casing 2, and Athe other section 40 is connected with the breech bolt i) through the medium of an arm'41, into which arm said bolt has screw-threadedengagement. rlhe cylinder section 40 is provided with an inertia body 42, for obvious reasons. With this arrangen'lent of the accumulator, z'. e.. having the same disposed substantially exterior-ly of the breech casing 2, the breech bolt sleevemay be manually unlocked and vthe breech opened merely by moving the cylinder section 40 with tirehand.

ln the arrangement shown in F ig. S, the construction is substantially the same as that disclosed in Figs. 1 and 2, differing only in holebi@ lthat the locking engagement between the breech bolt sleeve 5 and the breech bolt 9 consists in tivo Spiral flanges i3 in lieu ol. the lugs l2.

In the construction shown in Fig. 9, the locking connection between the breech bolt sleeve 5 and the bolt 9 consists in a pair of rectangular lugsnel4, one being shown, engaging Within straight guidewaysv 45. Said guidewajvs 45 enter into a cylindrical recess 4G, which permits of the breech bolt sleeve 5 being turned te lock or unlock when the lugs 4 enter therein.

In the arrangement shown in F ig. 10, the means for locking with the breech casing consists of lugs disposed on opposite sides of said bolt Sleeve, and each comprising two sections 47 and 48. The section 47 has a relatively steep spiral Surface 49 for engaging with a. like surface on the breech casing for electing'the locking engagement, and the section 48 has a relatively small surface 50, which engages With a similar element in the breech casing for terminating the unlocking operation. Each ot said sec-I tions has a relatively square surface 5l that engages with alike elementin the breech casing and provides shoulders or abutments, to the end of holding the breech bolt Sleeve against resistance or shock incident to tiring'.

The safety device combined with the cartridge holder 58, forms the subject-matter of another application, and need not, therefore, be' described or further disclosed in the present case.

It is obvious .that those skilled in the art may vary the details of construction and arrangement of parts without departing from the spirit of myinvention, and therefore l do Ynot wish to be limited to such features except as may be required by the claims.

What is claimed is:-

l. ln a firearm having a breech casing, the combination of a breech bolt sleeve mounted within said casing and having a rotary loching connection therewith; a breech bolt; means tor guiding the breech bolt rectilinear-ly within said breech casing; a rotary locking connection between the breech bolt sleeve and breech bolt; a breech bolt plug mounted within the breech bolt sleeve and having limited movement therein. said breech bolt plug having a portion in contact with the breech bolt and having a shoulder norinalljv spaced forward from the end of the breech bolt sleeve; said contacting portion operable to impart movement to the breech bolt to effect initial unlocking movement ct' the breech bolt sleeve` and said breech bolt plug cooperative with the breech bolt to completely,7 unlock and open the breech bolt sleeve through ga? pressure; and an' accumulator for automatically closing and locking the breech bolt sleeve7 subetantialljt7 as described.

2. In a firearm having' a breech casing, the combination of a breech bolt sleeve mounted Within said casing and having rotar;Y loching connection therevith; a breech bolt mounted Within and carried by the breech bolt sleeve; means for guiding the breech bolt rectilinearly in the breech casing: a rotaryv locking connection betuieen the breech bolt sleeve and breech bolt operable to loch and unlock the breech bolt sleeve; a tiring pin rectilinear-ly movable within the breech bolt; a breech bolt plug mounted within the breech bolt sleeve and providing a base l'or the cartridge, Said breech bolt plug movable axiallyA independeinl;1 ot' the breech bolt sleeve and operable to impart the initial unlocking movement thereto; a cartridge shell extractorT carried by said breech bolt plug; 'said plug operable to ei'ect the complete unlocking and opening otl the breech bolt sleeve through gas pressure; and an inertia bocy and accumulator tor automatically closing and locking the breech bolt sleeve, substantiallj7 as described.

ln a lirearm having a breech casing, the combination of a breech bolt sleeve having rotary locking connection with said casing; a breech bolt operable to unlock and open Said breech bolt sleeve through gas pressure 

